The invention relates generally to a thermal management system. More particularly, the invention relates to a system having an enhanced thermal management design and structure.
With the development of more sophisticated electronic components, systems are subject to increasingly demanding power density levels. The heat generated during operation of these components can degrade the performance and reliability of the overall system and can even cause system failure.
With the increased need for heat dissipation from microelectronic devices caused by these conditions, thermal management becomes an increasingly important element of the design of electronic products. As noted, both performance reliability and life expectancy of electronic equipment are inversely related to the component temperature of the equipment.
Contemporary aircraft use avionics to control the various equipment and operations for flying the aircraft. The avionics may be stored in an avionics chassis that performs several beneficial functions, such as electrically shielding the avionics from electromagnetic interference (EMI), protecting the avionics from lightning strikes, dissipating the heat generated by the avionics, and protecting the avionics from environmental exposure.
Thermal management of electronics is a key element in the avionics systems, especially in the event of loss of air cooling. A reduction in overall thermal resistance of the system including the card and the chassis may be obtained by enhancing heat extraction, spreading, and convection techniques to dissipate the heat from the chip to the ambient using heat pipes, fin optimization for natural convection and forced convection techniques. In aviation electronics, higher thermal mass was used to store the heat by using larger heat sinks. Phase change materials (PCM) such as waxes are used to store dissipated thermal energy. Further, thermal conductivity of the phase change materials were increased by the use of higher thermal conductivity additives, use of simple metal fins submerged in the PCM and use of metal foams.
While the aforementioned heat dissipation enhancement strategies are useful to the steady state cooling of avionics, a need exists to offset peak thermal loads and dampen transients to increase the reliability and life of avionics. A further need exists to store heat from the system in the event of loss of supplied cooling air from the aircraft, thereby providing additional time for the avionics to perform its operation without compromising functionality. Therefore, a reduction in thermal resistance of the PCM is desirable.